Microphone on wireless earphones doesn’t work

So I have my iPhone 13 and some quality Bluetooth earbuds for about a year now. The earbuds are connected to my iPhone and I have no problem regarding listening. The problem is I cannot use the microphone. When on calls or recording, while my earbuds are connected, it is dead silence.

After contacting the earbuds’ manufacturer they said to make sure that Bluetooth microphone usage is enabled on my phone, which I do not know how to check.

I would appreciate some help.